Harding selects musicians for each Dumb Numbers project from a large group of friends and collaborators.”[1][2] Lou Barlow, Dale Crover, Bobb Bruno (of Best Coast) and others contributed to the first two studio albums.

[3] A genre-defying act, Dumb Numbers musical style has been described variously as doom, sludge, and "swooning feedback pop", however there is general agreement that none of these labels are definitive.

Prior to the debut of Dumb Numbers, Harding was better-known as a videographer (having directed music videos for DJ Shadow, Warpaint, Best Coast, Swervedriver, Sebadoh, Lou Barlow, and Magic Dirt).

[12] The list of personnel involved with Dumb Numbers include, but is not exclusive to: Adam Harding, Murph (of Dinosaur Jr.), Bonnie Mercer (Warpaint, Swans), Steve Patrick (Useless Children, Magic Dirt), Lou Barlow (of Dinosaur Jr., Sebadoh, Folk Implosion et al), Dale Crover (of Melvins, Altamont, Nirvana), Toshi Kasai (of Deaf Nephews Studio in Los Angeles), David Yow (of Scratch Acid, The Jesus Lizard, Qui, Flipper), Bobb Bruno (of Best Coast), Thor Harris (Swans, Thor & Friends), Jenny Lee Lindberg (Warpaint) and others.

Personnel who consistently appear onstage during Dumb Numbers shows include Harding, Murph (of Dinosaur Jr.), Bonnie Mercer, and Steve Patrick.